Multifocal intraocular lens

ABSTRACT

An intraocular lens for providing a subject with vision at various distances includes an optic having a first surface with a first shape, an opposing second surface with a second shape, a multifocal refractive profile, and one or more diffractive portions. The optic may include at least one multifocal diffractive profile. In some embodiments, multifocal diffractive and the multifocal refractive profiles are disposed on different, distinct, or non-overlapping portions or apertures of the optic. Alternatively, portions of the multifocal diffractive profiles and the multifocal refractive profiles may overlap within a common aperture or zone of the optic.

FIELD OF THE INVENTION

The present application generally relates to lenses and related methodsthat can replace or supplement the lens of a human eye, moreparticularly to multifocal lenses and related methods that provide twoor more optical powers within a single optic or optical zone.

BACKGROUND OF THE INVENTION

Intraocular lenses (IOLs) and other ophthalmic lenses have beenconfigured to provide multiple foci, for example, to provide bothdistant vision and near vision to a subject, thus at least approximatingthe accommodative ability of the natural lens in a younger subject.Examples of such lenses are disclosed in U.S. Pat. No. 6,536,899 toFiala; U.S. Pat. Nos. 5,225,858; 6,557,998; 6,814,439; 7,073,906 toPortney; U.S. Pat. No. 7,188,949 to Bandhauer; and U.S. Pat. No.7,093,938 to Morris, all of which are herein incorporated by referencein their entirety.

Such multifocal or bifocal ophthalmic lenses may generally be classifiedas multifocal diffractive lenses or multifocal refractive lenses.Various advantages and disadvantages have been associated with eachclass or type of multifocal lens. One approach for incorporating thebenefits of each class of multifocal lens is to use a multifocaldiffractive lens in one eye and a multifocal refractive lens in theother eye.

A common problem with multifocal IOLs is that of halo patterns or imagesthat can occur when an out-of-focus image associated with one of thefoci is superimposed with an in-focus image associated with anotherfocus of the lens. For example, a distant automobile headlight, whenseen through a typical diffractive bifocal lens, appears as an in-focusspot on the retina of the eye and an out-of-focus blur spot surroundingthe in-focus spot and having a distinct outer border. This distinctouter border has been found to be annoying to users and various effortshave been made to soften this border so that the halo spot is lessnoticeable.

Multifocal ophthalmic lenses are needed that incorporate the advantagesof both multifocal diffractive and multifocal refractive intraocularlenses within a single optic in synergistic ways that enhance theoptical performance over traditional multifocal lenses and/or reduce theeffects of halo images.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an eye containing a natural crystalline lens.

FIG. 2 is a side view of the eye in FIG. 1 with an intraocular lensaccording to an embodiment of the present invention.

FIG. 3 is a side view of a cross-section of the intraocular lens shownin FIG. 2 showing diffractive and refractive profiles and theirassociated base shapes or curvatures.

FIG. 4 is a side view of a cross-section of the intraocular lens shownin FIG. 2.

FIG. 5 is a plan view of the posterior surface of the intraocular lensshown in FIG. 4.

FIG. 6 is a plot of the refractive add power of a multifocal refractiveprofile for the intraocular lens shown in FIG. 5.

FIG. 7 is side view of a cross-section of a multifocal lens accordinganother embodiment of the present invention.

FIG. 8 is a side view of a cross-section of a multifocal lens accordingto yet another embodiment of the present invention.

FIG. 9 is a plot of refractive and diffractive characteristics of themultifocal lens shown in FIG. 8.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention is directed to multifocal lenses, lens systems,and associated methods of making or use thereof. Embodiments discussedherein are generally directed to intraocular lenses; however, othertypes of lenses are anticipated, especially other types of ophthalmiclenses, such as contact lenses, corneal implants, spectacles, and thelike. In some embodiments, a corneal surgical procedure, such as a LASIKor PRK procedure, are conducted to provide optical aspects of the lensesdiscussed below.

In certain embodiments, an optic provides multifocal and/or extendedfocus performance through the use of a multifocal refractive element orprofile in combination with a diffractive element or profile. Thediffractive element may be a bifocal or multifocal diffractive element,wherein light within the visible range of the electromagnetic spectrumis directed two or more diffraction orders and/or foci. Alternatively,the diffractive element may be a monofocal diffractive element, whereinlight within the visible range of the electromagnetic spectrum isdirected completely or substantially completely to a single diffractionorder and/or focus. In certain embodiments, a multifocal diffractiveprofile is provided on all or part of one surface of an optic, while amultifocal refractive profile is provided on all or part of an oppositesurface of the optic. Alternatively, the multifocal diffractive profileand the multifocal refractive profile may be provided on a commonsurface. In some embodiments, multifocal diffractive and the multifocalrefractive profiles are disposed on different, distinct, ornon-overlapping portions or apertures of the optic. Alternatively,portions of the multifocal diffractive profiles and the multifocalrefractive profiles may overlap within a common aperture or zone of theoptic. In any of these embodiments, combinations of a multifocalrefractive element with a diffractive element may be configured to offera design or designer more flexibility in providing a predeterminedbalance between near and distant vision as a function of pupil size orlighting conditions. Such combinations also be configured to soften haloimages by providing more flexibility and design parameters for adjustingthe distribution of light within a halo cross-section.

As used herein, the terms “about” or “approximately”, when used inreference to a Diopter value of an optical power, mean within plus orminus 0.5 Diopter of the referenced optical power(s). As used herein,the terms “about” or “approximately”, when used in reference to apercentage (%), mean within plus or minus one percent (±1%). As usedherein, the terms “about” or “approximately”, when used in reference toa linear dimension (e.g., length, width, thickness, distance, etc.) meanwithin plus or minus one percent (1%) of the value of the referencedlinear dimension.

As used herein, the terms “light” or “visible light” meanelectromagnetic radiation within the visible waveband, for example,electromagnetic radiation with a wavelength in a vacuum that is between390 nanometers and 780 nanometers. As used herein, the term “opticalpower” of a lens or optic means the ability of the lens or optic toconverge or diverge light to provide a focus (real or virtual) whendisposed within a media having a refractive index of 1.336 (generallyconsidered to be the refractive index of the aqueous and vitreous humorsof the human eye), and is specified in reciprocal meters or Diopters(D). See ISO 11979-2. As used herein the terms “focus” or “focal length”of a lens or optic is the reciprocal of the optical power. As usedherein the term “power” of a lens or optic means optical power. As usedherein, the term “refractive power” or “refractive optical power” meansthe power of a lens or optic, or portion thereof, attributable torefraction of incident light. As used herein, the term “diffractivepower” or “diffractive optical power” means the power of a lens oroptic, or portion thereof, attributable to the diffraction orconstructive interference of incident light into one or more diffractionorders. Except where noted otherwise, optical power (either absolute oradd power) of an intraocular lens or associated optic is from areference plane associated with the lens or optic (e.g., a principalplane of an optic). In this respect, an intraocular lens with a base oradd power of 4.0 Diopters is approximately equal to an optical power ofabout 3.2 Diopters in a spectacle lens.

As used herein, the term “clear aperture” means the opening of a lens oroptic that restricts the extent of a bundle of light rays from a distantsource that can be imaged or focused by the lens or optic. The clearaperture is typically circular and specified by its diameter, althoughother shapes are acceptable, for example, oval, square, or rectangular.Thus, the clear aperture represents the full extent of the lens or opticusable for forming a conjugate image of an object or for focusing lightfrom a distant point source to a single focus, or to a plurality ofpredetermined foci in the case of a multifocal optic or lens. It will beappreciated that the term clear aperture does not limit thetransmittance of the lens or optic to be at or near 100%, but alsoincludes lenses or optics having a lower transmittance at particularwavelengths or bands of wavelengths at or near the visible range of theelectromagnetic radiation spectrum. In some embodiments, the clearaperture has the same or substantially the same diameter as the optic.Alternatively, the diameter of the clear aperture may be smaller thanthe diameter of the optic, for example, due to the presence of a glareor posterior capsular opacification (PCO) reducing structure disposedabout a peripheral region of the optic.

As used herein, the term “diffraction efficiency” is defined as thelight energy, power, or intensity at a particular wavelength that isdiffracted into a particular diffraction order of a diffractive optic,element, or portion divided by the total light energy, power, orintensity at the particular wavelength that is useful in providingvision or that is contained in all diffractive orders configured toprovide near, intermediate, or distant vision when placed in a model eye(real or mathematical) or in an eye of a patient or mammalian subject.By this definition, a monofocal diffractive optic, element, or portionhas a diffraction efficiency of 100%, while a multifocal diffractiveoptic, element, or portion with blazed profile configured to producezeroth and first diffraction orders in the visible range has adiffraction efficiency of 50% for each of two foci in the visible.

A multifocal optic, lens, refractive profile or structure, ordiffractive profile or structure is generally characterized by basepower and at least one add power. As used herein the term “base power”,when used in reference to an optic or lens, means a power (in Diopters)of an optic or lens required to provide distant vision at the retina ofa subject eye. As used herein the term “base power”, when specificallyapplied to a refractive profile or diffractive profile, means areference power (e.g., zero or about zero Diopters, or the power of alower diffraction order of the diffractive profile used to provide moredistant vision) from which one or more add powers of the profile orstructure may be measured or compared. As used herein, the term “addpower” means a difference in optical power (in Diopters) between a basepower and a second power of an optic, lens, profile, or structure. Whenthe add power is positive, the sum of the add power and the base powercorresponds to a total optical power suitable for imaging an object atsome finite distance from an eye onto the retina. A typical maximum addpower for an optic or lens is the range of about 3 Diopter to about 4Diopters in the plane of the lens; however, this number may be as highas 6 Diopters or more. An add power in Diopters may be directly relatedto an object distance from an eye by the relationship d=1/D, where d isthe object distance in meters and D is the add power in Diopters. Forexample, an add power of 1 Diopter is suitable for focusing an objectonto the retina that is located at a distance of 1 meter from anemmetropic eye in a disaccommodative state (e.g., with a relaxed ciliarymuscle), while add powers of 0.5 Diopter, 2 Diopters, 3 Diopters, and 4Diopters are suitable for focusing an object onto the retina that islocated at a distance of 2 meters, 50 cm, 33 cm, and 25 cm,respectively, from an emmetropic eye in a disaccommodative state.

As used herein, the term “near vision” means vision produced by an eyethat allows a subject to focus on objects that are at a distance of 40cm or closer to a subject (i.e., at least 2.5 Diopters of add power),typically within a range of 25 cm to 33 cm from the subject (i.e., 3Diopters to 4 Diopters of add power), which corresponds to a distance atwhich a subject would generally place printed material for the purposeof reading. As used herein, the term “intermediate vision” means visionproduced by an eye that allows a subject to focus on objects that arelocated between 40 cm and 2 meters from the subject (i.e., having an addpower between 2.5 Diopters and 0.5 Diopters). As used herein, the term“distant vision” means vision produced by an eye that allows a subjectto focus on objects that are at a distance that is greater than 2meters, typically at a distance of about 5 meters from the subject, orat a distance of about 6 meters from the subject, or greater.

Referring to FIG. 1, a cross-sectional view of a phakic eye containingthe natural crystalline lens is shown in which an eye 10 includes aretina 12 that receives light in the form of an image produced whenlight from an object is focused by the combination of the optical powersof a cornea 14 and a natural crystalline lens 16. The cornea 14 and lens16 are generally disposed about an optical axis OA. As a generalconvention, an anterior side is considered to be a side closer to thecornea 14, while a posterior side is considered to be a side closer tothe retina 12.

The natural lens 16 is enclosed within a capsular bag 20, which is athin membrane attached to a ciliary muscle 22 via zonules 24. An iris26, disposed between the cornea 14 and the natural lens 16, provides avariable pupil that dilates under lower lighting conditions (mesopic orscotopic vision) and constricts under brighter lighting conditions(photopic vision). The ciliary muscle 24, via the zonules 24, controlsthe shape and position of the natural lens 16, allowing the eye 10 tofocus on both distant and near objects. It is generally understood thatdistant vision is provided when the ciliary muscle 22 is relaxed,wherein the zonules 24 pull the natural lens 16 so that the capsular bag20 and lens 16 are generally flatter and provide a longer focal length(lower optical power). It is generally understood that near vision isprovided when the ciliary muscle contracts, thereby relaxing the zonules24 and allowing the capsular bag 20 and lens 16 to return to a morerounded state that produces a shorter focal length (higher opticalpower).

Referring to FIG. 2, a cross-sectional view of a pseudophakic eye isshown in which the natural crystalline lens 16 has been replaced by anintraocular lens 100 according to an embodiment of the presentinvention. The intraocular lens 100 comprises an optic 102 and haptics103, the haptics 103 being configured to at least generally center theoptic 102 within the capsular bag 20, provide transfer of ocular forcesto the optic 102, and the like. Numerous configurations of haptics 103relative to optic 102 are well know within the art, and embodiments ofthe present invention may generally be applied to any of these. Theoptic 102 is configured to provide two or more foci, for example, toprovide a subject with both distant vision and near vision, to provide asubject with both distant vision and intermediate vision, or provide asubject with distant vision, intermediate vision, and near vision, as isexplained in greater detail below.

Referring to FIGS. 3-5, only the optic 102 of the intraocular lens 100is shown (i.e., haptics 103 are not shown). The optic 102 comprises ananterior surface 104 and an opposing posterior surface 106. The optic102 also has a clear aperture 107 disposed about the optical axis OA.The anterior surface 104 has an anterior base shape, figure, orcurvature 114, while the posterior surface 106 has a posterior baseshape, figure, or curvature 116. The base shapes 114, 116 provide a baseoptic 102 power that generally provides distant vision. The base optic102 power is generally between −20 Diopters and +60 Diopters, typicallybetween about +10 Diopters and about +40 Diopters.

The optic 102 also includes a multifocal refractive profile or element124 imposed on, added to, or combined with the anterior base shape 114.In the illustrated embodiment, the refractive profile 124 issymmetrically disposed about the optical axis OA over a radial extentfrom the optical axis OA that includes the entire clear aperture 107 ofthe optic 102. Alternatively, the refractive profile 124 may beasymmetric disposed, may have a radial extent that is less than theentire clear aperture 107, and/or may have an inner radius that startsas a predetermined distance from the optical axis OA. The multifocalrefractive profile 124 in FIGS. 3 and 4 is an undulating surface thathas been exaggerated along the optical axis OA for illustrativepurposes. In general, the local optical power of the multifocalrefractive profile 124 is varied with radius from the optical axis OA byvarying the local radius of curvature. The multifocal refractive profile124 includes one or more portions having a base refractive power that iszero or about zero Diopter, or that has an average optical power that iszero or about zero Diopter. The multifocal refractive profile 124 alsoincludes one or more portions having an add power or average add powerthat is added to the base refractive power, typically having a value ofbetween about 1 Diopter and 4 Diopters. In some embodiments, themultifocal refractive profile 124 may include portions that have an addpower or average add power that is negative, for example, about −1Diopters.

With additional reference to FIG. 6, the refractive profile 124 of theillustrated embodiment includes a portion 125 a that has an averageoptical power of about zero Diopters. The multifocal refractive profile124 also includes an portion 125 b having an add power that variescontinually with radius and having a maximum refractive add power ofabout 2 Diopters. The multifocal refractive profile 124 also includes aportion 125 c having a constant power of zero Diopters, for example, toprovide additional distant vision for larger pupil sizes or underscotopic lighting conditions.

The optic 102 further includes a multifocal diffractive profile orelement 126 that is imposed on, added to, or combined with the posteriorbase shape 116. The multifocal diffractive profile 126 generallycomprises a central echelette 127 surrounded by a plurality of annularechelettes 128, whereby the height of steps 129 between adjacentechelettes 127, 128 (exaggerated in FIGS. 3, 4 for illustrativepurposes) and the shape of the echelettes 127, 128 are selected toprovide constructive interference between echelettes for incident lighton the optic 102 to produce two or more foci. The multifocal diffractiveprofile 126 may have, for visible light, a primary diffraction order, asecondary diffraction order, and a diffractive add power correspondingto a difference in optical power between the secondary diffraction orderand the primary diffraction order. In some embodiments, the primarydiffraction order is a zeroth diffraction order having an optical powerof or about zero Diopters and the secondary diffraction order is a firstdiffraction order having diffractive optical power that is between about2 Diopter and about 8 Diopters, so that the diffractive add power isequal to or approximately equal to the diffractive power of the seconddiffraction order. Alternatively, the primary diffraction order may be afirst diffraction order of the diffractive profile 126 and the secondarydiffraction order may be a second diffraction order of the diffractiveprofile 126 having an optical power tiat is between about 2 Diopter and8 Diopters greater than the optical power of the primary diffractionorder. In this case, the base power of the multifocal diffractiveprofile may be equal to the power of the primary diffraction order. Inany event, the diffractive add power is generally within the range ofabout 2 Diopters to 8 Diopter, or between about 3 Diopters and about 4Diopters. The latter range may correspond to both (1) a favorable amountof add power to provide near vision and (2) a degree of diffractivechromatic dispersion sufficient to reduce or eliminate a refractivechromatic aberration produced by the optic 102 and/or the cornea 14 ofthe eye 10. In certain embodiments, the diffractive add power is lessthan about 2 Diopter, for example, to provide an extended depth offocus, as disclosed in co-pending U.S. patent application Ser. No.12/197,249, which is herein incorporated in its entirety.

The multifocal profiles 124, 126 may represent deviations from the baseshapes 114, 116, respectively, these deviations providing the multifocalor other optical characteristics (e.g., chromatic correctioncharacteristics) of the optic 102. As illustrated in FIGS. 3 and 4, themultifocal profiles 124, 126 may be added on top of the base shapes 114,116. Alternatively, the base shapes 114, 116 may represent an averageprofile of the surfaces 104, 106, wherein the refractive profile 124 orthe diffractive profile 126 represents deviations above and below thisaverage surface profile.

The multifocal profiles 124, 126 have or provide an overlap portion 130defining an overlap aperture or zone 132, which represents an apertureor zone over which light from an object or point source incident on theoptic 102 passes through, and is acted upon by, both multifocal profiles124, 126. Thus, light or a wavefront incident on the overlap aperture132 is focused through interaction with both multifocal profiles 124,126. In the illustrated embodiment, the overlap aperture 132 is filledby only a portion of the multifocal refractive profile 124 and by theentire the multifocal diffractive profile. The extent of the multifocalprofiles 124 or 126 may be varied according to the requirements of aparticular design or application. The overlap aperture 132 may becircular, as in the illustrated embodiment, or may be annular or someother shape.

Alternatively, as illustrated in FIG. 7, an optic 102′ includes amultifocal refractive profile 124′ and a multifocal diffractive profile126′ that both extend over the entire clear aperture 107′ of the optic102′, wherein the overlap aperture 132′ is equal to or substantiallyequal to the clear aperture 107′. In such embodiments, the multifocaldiffractive profile 126′ may be replaced by a monofocal diffractiveprofile, whereby the multifocality of the optic 102′ is provided by themultifocal refractive profile 124′. The monofocal diffractive profilemay be configured to correct or compensate for chromatic aberrations ofthe two or more foci provided by the multifocal refractive profile 124′.The corrected chromatic aberration may be that of the optic 102′ itself,or that of the combination of the optic 102′ and the eye 10 (e.g., ofthe cornea 14).

In general, light passing through the overlap aperture 132 has at leastone combined add power produced by a combination of the refractive addpower and the diffractive add power. Light passing through the overlapaperture may also have additional foci or add powers apart from combinedadd power. In the illustrate embodiment, for example, the multifocaldiffractive profile 126 may be configured to split incident lightbetween a zeroth diffraction order having zero optical power and a firstdiffraction order having 2 Diopters of optical power. As seen in FIG. 6,the base portion 125 a of the multifocal refractive profile 124 has anaverage add power of about zero Diopters, while the add portion 125 b ofthe multifocal refractive profile 124 has an add power of about 2Diopters. Light passing through both the base portion 125 a of themultifocal refractive profile 124 and the diffractive profile 126 issplit into two foci, one with a power equal to the base optic 102 power(e.g., 20 Diopters based on the combined refraction of the base shapes114, 116) and another with a refractive power equal to the base optic102 power plus the 2 Diopters of diffractive add power provided by thefirst diffraction order. Light passing through the add portion 125 b ofthe multifocal refractive profile 124 and the multifocal diffractiveprofile 126 is split into two foci, one with approximately 2 Diopters ofadd power plus the base optic 102 power and another with about 4Diopters of add power plus the base optic 162 power (the about 4Diopters coming from about 2 Diopters of refractive power from the addportion 125 b and 2 Diopters of diffractive add power from the firstdiffraction order). Thus, in this example, the optic 102 over theoverlap aperture 132 to advantageously provides at least three foci whenthe base optic 102 power produced by the base shapes 114, 116 isincluded (e.g., 20 Diopters, 22 Diopters, and 24 Diopters, for a baseoptic 102 power of 20 Diopters, a multifocal refractive add power ofabout 2 Diopters, and a multifocal diffractive add power of 2 Diopters).The combination of refractive and diffractive add powers may beadvantageously configured to reduce halo effects or to otherwise utilizethe distinct advantages of each type (refractive or diffractive)multifocal profile or element. For example, the diffractive profile maybe configured to provide a predetermined relationship between the amountof light energy, power, or intensity in near and distant foci that isindependent of the area or diameter of pupil size or lightingconditions.

In some embodiments, the refractive add power is between about 1 Diopterand about 3 Diopters and the diffractive add power is between about 1Diopter and about 3 Diopters. The optic 102 may have a total add powerwithin the overlap aperture 132 that is between about 3.5 Diopter andabout 4.5 Diopters. In some embodiments, the diffractive add powerand/or the refractive add power is selected to provide intermediatevision, while the total add power (the combination of the diffractiveand refractive add powers) is able to provide near vision.

In the illustrated embodiment, the multifocal refractive profile 124 isdisposed on an optic 102 surface opposite that on which the multifocaldiffractive profile 126 is disposed; however, both profiles 124, 126 maybe disposed on a common surface. For example, the both profiles 124, 126may be both be imposed on either the anterior shape 114 or the posteriorshape 116. Other variations from the design shown in FIGS. 3-6 are alsoanticipated. For example, the multifocal refractive profile 124 may bedisposed on the posterior base shape 116 and/or the multifocaldiffractive profile 126 may be disposed on the anterior base shape 114.In general, the optic may comprise other refractive and/or diffractiveprofiles in addition to the profiles 124, 126, wherein one or more ofthe refractive profiles define one or more overlap portions, zones, orapertures with one or more of the diffractive profiles.

The general shape of the optic 102, as defined by the base shapes 114,116, may be biconvex, plano-convex, plano-concave, meniscus, or thelike. The optic 102 may include a Fresnel surface or profile. In certainembodiments, the base shapes 114, 116, or portions thereof, arespherical and each shape 114, 116 or portion thereof is characterized byradius of curvature. In such embodiments, a base optic 102 power isdeterminable based on the radius of curvature of each shape 114, 116 orportion thereof, the refractive index of the optic 102 material, and therefractive index of the media into which the intraocular lens 100 isplaced. In some embodiments, one or both the shapes 114, 116 may beaspheric, for example to correct, cancel, or at least partiallycompensate for a spherical aberration of the eye 10 (e.g., the cornea14) and/or the optic 102. In such embodiments, the aspheric surface maybe characterized by an equation for a conic section containing a radiusof curvature and/or a conic or asphericity constant over all or aportion of the optic shape or surface. For example, in certainembodiments, one or both base shapes 114, 116 of the optic 102 may havea shape or profile that is represented by a so-called sag Z given by theequation:

$\begin{matrix}{{Z(r)} = \frac{r^{2}/R}{1 + \sqrt{1 - {{r^{2}\left( {{CC} + 1} \right)}/R^{2}}}}} & (1)\end{matrix}$where r is a radial distance from the center or optical axis of thelens, R is the radius or curvature at the center of the lens, CC is theso-called conic constant. This equation may represent the sag Z over anentirety of one or both base shapes 114, 116, or over a particular zone,annular region, or some other shaped region of the base shapes 114, 116.

In certain embodiments, the one or both base shapes 114, 116 arecharacterized by an equation for a conic section and one or more higherorder polynomials in radius from the optical axis over all or a portionof the optic surface. Examples of such aspheric shapes are disclosed inU.S. Pat. Nos. 6,609,793; 6,830,332; 7,350,916 to Hong et al.; and USPatent Application No. 2004/0156014, all of which are hereinincorporated by reference. For example, one or both base shapes 114, 116may have a base shape or profile represented by sag Z given by anequation:

$\begin{matrix}{{Z(r)} = {\frac{r^{2}/R}{1 + \sqrt{1 - {{r^{2}\left( {{CC} + 1} \right)}/R^{2}}}} + {ADr}^{4} + {AEr}^{6} + \ldots}} & (2)\end{matrix}$where r is a radial distance from the center or optical axis of thelens, R is the radius of curvature at the center of the lens, CC is aconic constant, and AD and AE are polynomial coefficients additional tothe conic constant CC. This equation may represent the sag Z over anentirety of one or both base shapes 114, 116, or over a particular zone,annular region, or some other shaped region of the base shapes 114, 116.

One or both base shapes 114, 116 of the optic 102 may have a shape orcurvature that is represented by an equation containing one or morecoefficients for other types of polynomial equations, such as a Zernikepolynomial a Fourier polynomial, or the like. One or both base shapes114, 116, may also be non-symmetric, for example, having a toric shapefor correcting an astigmatism of the cornea 14. In addition, the one orboth base shapes 114, 116 of the optic 102 may be segmented, forexample, comprising segmented annular segments described by differentequations or different coefficient values. In such embodiments, thesegments may be joined together as a spline.

An aspheric shape of one or both base shapes 114, 116 of the optic 102may be configured to produce an aberration, for example to counteract,reduce, or eliminate one or more aberrations of the optic 102 and/or eye10 (e.g., the cornea 14). In some embodiments, the aspheric shape isconfigured to counteract, reduce, or eliminate aberrations introducedinto an incident wavefront, for example, into a wavefront from acollimated wavefront, a distant point source, and/or the cornea 14 ofthe eye 10. The aberration produced or corrected by the optic 102, orsome zone or portion thereof, may be astigmatism or a sphericalaberration. Additionally or alternatively, the aberration produced orcorrected by the optic 102, or some zone or portion thereof, may be achromatic aberration or a higher order monochromatic aberrations such ascoma, trefoil, or the like.

The intraocular lens 100 may be configured for insertion into or infront of the capsular bag 20. Alternatively, the intraocular lens 100may be configured to be located in the anterior chamber in front of theiris 26. In addition, the optic 102 or the intraocular lens 100 may beconfigured to be an add-on or piggy-back lens that is used to supplementa second intraocular lens or optic.

The optic 102 or the intraocular lens 100 may be configured to provideaccommodation. For example, the optic 102 may be made from a relativelysoft material and sized to fill capsular bag 20. Alternatively, theoptic 102 may be attached to haptics or an optic positioning elementthat either moves the optic 102 along the optical axis OA and/or changesshape in response to an ocular force produced by a ciliary muscle,zonules, and/or a capsular bag. In such embodiments, the optic 102 maybe combined with one or more additional optics. The accommodatingintraocular lens may additionally or alternatively provide accommodationby axial rotation of the optic or based on the so-called Alvarezprinciple (e.g., based on translation of the optic either axially ortransversely).

In certain embodiments, the multifocal diffractive profile 126 of theoptic 102 may be replaced by, or supplemented by, a monofocaldiffractive profile. The monofocal diffractive profile may be configuredto have only one diffraction order in the visible band that produces orprovides a focus. Alternatively, the monofocal diffractive profile maybe configured to have a high MOD profile, whereby a plurality ofdiffraction orders of the monofocal diffractive profile focus light atdifferent wavelengths to a single focus or substantially a single focus(e.g., as disclosed in U.S. Pat. No. 7,093,938 to Morris).

The multifocal refractive profile 124 may provide a relatively lowamount of add power, for example, within a range of about 1 Diopter toabout 2 Diopter (e.g., to provide distant and intermediate vision).Alternatively, the multifocal refractive profile 124 may includeportions that provide a relatively high add power, for example, havingan optical power from about 3 Diopter to about 4 Diopter (e.g., toprovide distant and near vision) or from about 3 Diopters to about 6Diopters. The monofocal diffractive profile may be disposed on the samesurface or opposite surface as the multifocal refractive profile 124.One advantage of the combination of a monofocal diffractive profile incombination with a multifocal refractive profile is that all the foci ofthe lens or optic have the same or similar amounts of correction forchromatic aberrations. In some embodiments, an optic or lens comprisesboth a monofocal diffractive profile and a multifocal diffractiveprofile, wherein the profiles are contained on the same or oppositesurfaces. In such embodiments, one or both diffractive profiles have anaperture that is less than the clear aperture of an optic or lens.

The profiles 124, 126 may be machined or cast to form the surfaces 104,106 using conventional techniques know in the art. The spacing and shapeof the echelettes of the diffractive profile 126 are generally accordingto those known within the art for forming monofocal, bifocal, ormultifocal diffractive intraocular lenses, contact lenses, or the like;for example, as disclosed in various patents to Allen Cohen, MichaelFreeman, John Futhey, Patricia Piers, Chun-Shen Lee, Michael Simpson,and others. The profiles 124, 126 may be a physical profile, asillustrated in FIGS. 3 and 4. Alternatively, one or both of the profiles124, 126 may be replaced or supplemented by a gradient index within theoptic 102 that is configured to provide the same or a similar refractiveand/or diffractive effect to that produced by the profiles 124, 126.

The intraocular lens 100, as well as other intraocular lenses discussedherein, may be constructed of any of the various types of material knownin the art. For example, the intraocular lenses according to embodimentsof the present invention may be a foldable lens made of at least one ofthe materials commonly used for resiliently deformable or foldableoptics, such as silicone polymeric materials, acrylic polymericmaterials, hydrogel-forming polymeric materials (e.g.,polyhydroxyethylmethacrylate, polyphosphazenes, polyurethanes, andmixtures thereof), and the like. Other advanced formulations ofsilicone, acrylic, or mixtures thereof are also anticipated. Selectionparameters for suitable lens materials are well known to those of skillin the art. See, for example, David J. Apple, et al., IntraocularLenses: Evolution, Design, Complications, and Pathology, (1989) William& Wilkins, which is herein incorporated by reference. The lens materialmay be selected to have a relatively high refractive index, and thusprovide a relatively thin optic, for example, having a center thicknessin the range of about 150 microns to about 1000 microns, depending onthe material and the optical power of the lens. At least portions of theintraocular lens, for example one or more haptics or fixation membersthereof, may be constructed of a more rigid material including suchpolymeric materials as polypropylene, polymethylmethacrylate PMMA,polycarbonates, polyamides, polyimides, polyacrylates,2-hydroxymethylmethacrylate, poly (vinylidene fluoride),polytetrafluoroethylene and the like; and metals such as stainlesssteel, platinum, titanium, tantalum, shape-memory alloys, e.g., nitinol,and the like. In some embodiments, the optic and haptic portions of theintraocular lens are integrally formed of a single common material.

In the illustrated embodiments of FIGS. 3-7, optics 102, 102′ areconfigured so the light incident on at least portions thereof(specifically on the overlap aperture 132) interact with two multifocalprofiles (profiles 124, 126 or profiles 124′, 126′). In certainembodiments, it may be beneficial to configure various multifocalprofiles (refractive and diffractive) such that light incident upon someor all sub-apertures of the optic generally interacts with only a singlemultifocal profile at a time (either refractive or diffractive).

For example, referring to FIG. 8, in certain embodiments an optic 202includes an anterior surface 204 and an opposing posterior surface 206,where the anterior surface 204 has an anterior shape, figure, orcurvature 214 and the posterior surface 206 has a posterior shape,figure, or curvature 216, wherein the shapes 214, 216 together provide abase optic 202 power. The optic 202 includes an inner or central zone230 disposed about an optical axis OA extending out to a radius r1, anintermediate zone 232 disposed about the inner zone 230 extending over arange from r1 to r2, and an outer zone 234 disposed about theintermediate zone 232 extending over a range from r2 to r3. The innerzone 230 is circular when viewed from a front view of the optic 202,while the zones 232, 234 are annular; however, other shapes are possible(e.g., the inner zone 230 may also be annular, or any of the zones maybe oval or some other shape). As used herein, a “zone” of an opticincludes any features of, or between, the anterior and posteriorsurfaces 204, 206 located within the radial boundaries of the zonerelative to an optical axis (e.g., in the case of an annular zone,between inner and outer radii from an optical axis of an optic).

The optic 202 also includes a first diffractive profile 226A imposed onthe posterior shape 216 and located within the inner zone from theoptical axis OA out to radius r1. The optic 202 also includes a seconddiffractive profile 226B imposed on the posterior shape 216 and locatedwithin the outer zone 234 from radius r2 out to radius r3. The optic 202additionally includes a multifocal refractive profile 224 that isimposed on the anterior shape 214 and includes a refractive add portion224A having refractive add power. The refractive add portion 224A isradially disposed intermediate the diffractive profile 226A, 226B andwithin the intermediate zone 232 and has a radial extent from r1 to r2

Either or both the diffractive profiles 226A, 226B may have, for visiblelight, a primary diffraction order having a first diffraction power, asecondary diffraction order having a second diffraction power, and anadd power corresponding to a difference between the first and seconddiffraction powers. In some embodiments, at least one of the diffractiveprofiles 226A, 226B is a monofocal diffractive profile having only asingle diffraction order producing a focus within the visible band ofthe electromagnetic spectrum, for example, to correct or compensate fora chromatic aberration or dispersion produced by the optic 202 and/orthe cornea 14 of the eye 10.

The diffractive profiles 226A, 226B and/or the multifocal refractiveprofile 224 may be located on either the anterior or posterior surfaces204, 206. In the illustrated embodiment, the diffractive profiles 226A,226B are both disposed on the posterior surface 206, while therefractive profile 224, specifically the refractive add portion 224A, isdisposed on the opposite surface 204. Alternatively, one or bothdiffractive profiles 226A, 226B may be disposed on a common surface(e.g., the surface 204 or 206) with the refractive add portion 224A. Thezones 230, 232, 234, as defined by the diffractive profiles 226A, 226Band refractive add portion 224A, are generally adjacent to one anotherand may be configured to form contiguous surface or volume elements. Insome embodiments, the optic 202 includes transition zones disposedbetween one or more sets of adjacent zones (e.g., between zones 230, 232and/or between zones 232, 234). As such, transition zone surfaces may beconfigured to provide a smooth blending of the surface portions betweenadjacent primary zones. For example, if the profiles 224, 26A, 226B areon a single surface (surface 204 or 206), a transition zone surfacebetween adjacent profiles may be configured to blend these surfaceportion and/or to reduce glare that could be created by discontinuitiesor sharp borders at a junction between adjacent profiles. The anteriorand/or posterior surfaces 204, 206 over one or more adjacent zones maybe defined, in whole or in part, by one or more splines. Referring againto FIG. 8, the refractive add portion 224A is radially disposed betweenthe diffractive profiles 226A, 226B. The refractive add portion 224A mayhave a constant add power between r1 and r2, as illustrated in FIG. 9.Alternatively, the refractive add portion 224A may have an add powerthat varies between r1 and r2, for example, to provide multiple foci, anextended depth of focus, and/or both near vision and some intermediatevision (e.g., with an add power of about 3 Diopter to about 4 Dioptersfor near vision, and an add power of about 1 Diopter to about 2 Dioptersfor intermediate vision). The refractive add portion 224A may have arefractive add power that is equal to or substantially equal to thediffractive add power of the first and/or second diffractive profile226A, 226B, for example, about 3 Diopters to about 4 Diopters.Alternatively, the refractive add portion 224A may have a refractive addpower that is less than that of the diffractive add power of the firstand/or second diffractive profile 226A, 226B (e.g., to provideintermediate vision under mesopic or photopic lighting conditions, forexample, to allow a subject to focus on a computer monitor under typicalroom lighting conditions). In some embodiments, the multifocalrefractive profile 224 includes a base power that is zero or about zero,and includes one or more add powers for intermediate vision or nearvision (e.g., about 1 Diopter, about 2 Diopter, about 3 Diopters, orabout 4 Diopters).

In certain embodiments, the intermediate zone 232 has a constantrefractive optical power that is equal to a base power of the optic 202,for example, so that the intermediate zone 232 provides distant vision.In such embodiments, the multifocal refractive profile 224 includes azone or surface portion having an add power, for example, to providenear or intermediate vision. In one such embodiment, multifocalrefractive profile 224 include an add power for intermediate vision inthe inner zone 230 and/or the outer zone 234, wherein the multifocaldiffractive profile 226A and/or 226B is (are) configured to provideintermediate and near vision. In other embodiments, the multifocalrefractive profile 224 is replaced with a monofocal refractive profilehaving a constant refractive optical power, whereby the multifocaldiffractive profiles 226A, 226B are radially separated by a zone ofconstant refractive optical power for distant vision and no diffractiveoptical power. The monofocal refractive profile may comprise a sphericalsurface having a constant radius of curvature or may comprise anaspheric surface, for example, having a spherical aberration configuredto correct or reduce a spherical aberration of the optic 202 and/or theeye 10.

The diffractive profiles 226A, 226B and the refractive add portion 224Amay advantageously be configured to vary add power with radius from theoptical axis OA, both in terms of magnitude and type of focusingproduced (e.g., either diffractive or refractive). For example, it hasbeen found that the combination of a multifocal diffractive pattern ininner zone 230 and a refractive add or multifocal profile in moreperipheral regions (e.g., the intermediate zone 232) can offer distinctbenefits, such as the ability to reduce halo effects (e.g., as disclosedin U.S. Pat. No. 7,188,949 to Bandhauer), and more flexibility indistributing the light energy, power, or intensity in the near,intermediate, and far foci as the pupil diameter increases. For example,a design may utilize the principle that the amount of light energy,power, or intensity from a near focal point going into a particular haloor halo element depends on area, in the case of a multifocal refractiveprofile, but depends on echelette step height and/or shape in the caseof a multifocal diffractive profile.

The diffractive profiles 226A, 226B may be configured to have the sameor similar optical characteristics. For example, the diffractiveprofiles 226A, 226B may both be monofocal profiles having the same ordifferent diffractive optical powers. Alternatively, one or both of thediffractive profiles 226A, 226B may be multifocal profiles, wherein theeach profile 226A, 226B has the same diffractive optical power(s) (e.g.,the same base power and/or add power).

In certain embodiments, the diffractive profiles advantageously havedifferent optical characteristics. For example, one of the profiles226A, 226B may be a monofocal profile, while the other is a multifocalprofile. In other embodiments, each of the profiles 226A, 226B is amonofocal profile, but the diffractive optical power of each profile isdifferent (e.g., one configured to provide distant vision and the otherto provide intermediate or near vision). In yet other embodiments, eachof the profiles 226A, 226B is a multifocal profile, with each having adifferent optical characteristic. For example, the profiles 226A, 226Bmay have different diffraction efficiencies, different base or addpowers, different design wavelengths, and/or different echelette stepheights and/or echelette shapes.

Referring further to FIG. 9, a preferred embodiment of the profiles 224,226 is illustrated in which the profiles are configured to havedifferent optical characteristic in the form of different diffractionefficiencies. The lower plot of FIG. 9 shows the diffraction efficiencyof the diffractive profiles 226A, 226B as a function of distance fromthe optical axis OA, while the upper plot shows the add power of themultifocal refractive profile 224 as a function of the distance from theoptical axis OA. The scale of the horizontal axis of each plot in FIG. 9is the same, allowing comparison of the refractive add power anddiffraction efficiency at various distances from the optical axis OA.The diffraction efficiency of the diffractive profile 226A is 20%, fromthe optical axis out to the radius r1, while the refractive power of themultifocal refractive profile 224 is zero. Thus, within the inner zone230, the optic 202 has a base optic power provided by the combination ofthe anterior and posterior shapes 214, 216, and a diffractive add powerprovided by the first diffractive profile 226A, with approximately 20%of the useful light energy, power, or intensity from light at the designwavelength going to the diffractive add power (e.g., for providing nearor intermediate vision) and approximately 80% of the useful lightenergy, power, or intensity going into the base optic power (e.g., forproviding distant vision). The add power of the multifocal diffractiveprofile may be between about 2 Diopters and about 4 Diopters, althoughother diffractive add powers are possible (e.g., between about 1 Diopterand about 2 Diopters for providing intermediate vision and/or forproviding an enhanced depth of focus). It will be understood by those ofskill in the art that some light at the design wavelength and at otherwavelengths will be directed into other diffraction orders that aredifferent from the primary and secondary diffraction orders, the amountof light directed into higher and/or lower diffraction order dependingon the specific design of the first diffractive profile 226A.

Since there is not a diffractive grating or profile within theintermediate zone 232 in the illustrated embodiment, there is no addpower due to diffraction; however, between r1 and r2 the multifocalrefractive profile 224 includes the refractive add portion 224A which,in the illustrated embodiment, provides a refractive add power of 4Diopters, which is sufficient to provide near vision. Thus, for mediumpupil sizes (e.g., about 3 mm diameter) the optic 202 provides both adiffractive add power and a refractive add power. In some embodiments,the diffractive add power is also 4 Diopters and the optic 202 has twofoci, one corresponding to the base optic 262 power and onecorresponding to an add power that is produced by both the diffractiveprofile 226A and the refractive add portion 224A. Alternatively, therefractive add portion 224A may be or include a refractive add powerthat is less than the diffractive add power, for example, a refractiveadd power configured to provide intermediate vision or a differentamount of near vision (e.g., about 1 Diopter, about 2 Diopters, or about3 Diopters). In other embodiments, the refractive add portion 224A mayinclude at least two refractive add powers, and/or a continually and/ormonotonically varying add power (e.g., of about 3 Diopter and about 4Diopter; or continually increasing or decreasing from about 2 Dioptersto about 3 Diopters or about 4 Diopters).

Between the radii r2 and r3 of the illustrated embodiment for the optic202, the multifocal refractive profile 224 again has no add power, whilethe second diffractive profile 226B provides a diffractive add power.The profile 226B is configured to produce a 30% diffraction efficiency,wherein 30% of the useful light energy, power, or intensity at thedesign wavelength goes into providing a diffractive add power (e.g., fornear or intermediate vision) and approximately 70% of the useful lightenergy, power, or intensity going into a base optic power (e.g., fordistant vision). In some embodiments, the diffractive add power of thesecond diffractive profile 226B is the same as the diffractive add powerof the first diffractive profile 226A and/or is the same as therefractive add power provided by the refractive add portion 224A. Insome embodiments, the add powers of the zones 230, 232, 234 are eachdifferent, for example, to provide an extended depth of focus for largepupil diameters, to provide a predetermined distribution of lightenergy, power, or intensity between foci for given pupil diameter, orprovide a predetermined light energy, power, or intensity distributionwithin halos to reduce the effect thereof on a subject.

The effects of halos may be reduced by configuring the first and/orsecond diffractive profiles 226A, 226B to have diffraction efficienciesof less than 50%. One advantage of using a lower diffraction efficiencyis that both the amount and distribution of light within halos producedby the multifocal optic 202 may result in reduced halo effects. In someembodiments, the diffraction efficiency is between 10% and 40%, orbetween 15% and 35%. For example, in the illustrated embodiment, thediffraction efficiency of the first diffractive profile 226A is between15% and 25%, while the diffraction efficiency of the second diffractiveprofile 226B is between 25% and 35%. In the illustrated embodiment shownin FIG. 9, certain advantages in terms of halo effects may be providedby configuring the diffraction efficiency of the second diffractiveprofile 226B (disposed in the outer zone 234) to be greater than thediffraction efficiency of the first diffractive profile 226A (disposedin the inner zone 230). In other embodiments, the diffraction efficiencyof the second diffractive profile 226B is less than the diffractionefficiency of the first diffractive profile 226A.

In certain embodiments, the diffraction efficiency of one or both thediffractive profiles 226A, 226B are relatively high, for example, about50%, between about 40% and about 60%, or even greater than 60%. Forexample, the diffractive profile 226A may be relatively high so that asignificant amount of near vision is provided for a relatively smallpupil (e.g., having a diameter from about 2 mm to about 3 mm). In suchembodiments, or in other embodiments, the refractive add power of therefractive add portion 224A may be relatively small (e.g., between about1 Diopter and about 2 Diopters) or may be zero or about zero (e.g.providing only distant vision).

Other variations of the profiles shown in FIGS. 8 and 9 are anticipated.For example, inner and/or outer zones 230, 234 may contain a refractiveprofile in addition to, or in place of the diffractive profiles 226A,226B. In addition, the intermediate zone 232 may contain a diffractiveprofile in addition to, or in place of, the refractive add portion 224A.In certain embodiments, the zones 230, 232, 234 fill the entire clearaperture of the optic 202. In other embodiments, the optic 202 includesother multifocal diffractive and/or multifocal refractive zones, forexample, within the inner zone 230 or outside the outer zone 234. Incertain embodiments, the refractive add portion 224A has a relativelylow add power (e.g., between about 1 Diopter and about 2 Diopters), oreven a negative add power (e.g., less than a base power of therefractive profile 224). In such embodiments, the intermediate zonecontaining the refractive add portion 224A may also include a multifocalor monofocal diffractive profile, either on the same surface or oppositesurface containing the refractive add portion 224A.

In a preferred embodiment, one of the diffractive profiles 226A, 226B isa monofocal diffractive profile and the other profile 226A, 226B is amultifocal diffractive profile. For example, the optic 202 mayadvantageously be configured so that the inner diffractive profile 226Ais a multifocal diffractive profile, the intermediate refractive addportion 224A is multifocal refractive profile, and the outer diffractiveprofile 226B is a monofocal diffractive profile. In this embodiment,when the pupil size is smaller (e.g., under photopic lightingconditions), the multifocal diffractive profile 226A provides power forboth far focus and near focus that is relatively distinct and sharp ascompared to a refractive multifocal. Under such conditions, it has beenfound that there is less need to provide intermediate vision, sincesmaller pupil sizes inherently have relatively large depths of focus.Under mesopic lighting conditions, a multifocal refractive profile 224Afavorably provides advantages such as the ability of provide at leastsome intermediate vision, reduced halo effects, and/or more flexibilityin distributing the amount of light energy, power, or intensity in thenear, intermediate, and far foci as the pupil diameter increases. Theouter monofocal diffractive profile 226B corrects or reduces chromaticaberrations and provides more distant vision for larger pupil sizes, forexample, to provide better distant vision during night time driving.Alternatively, the outer monofocal diffractive profile 226B may beconfigured to provide near or intermediate vision.

The anterior and/or posterior shapes 214, 216, or portions thereof, maybe either spherical or aspheric, for example, comprising a shapedescribed by Equations 1 and 2 above, or described by a Zernikepolynomial, Fourier polynomial, or the like. One or both base shapes214, 216, may also be non-symmetric, for example, having a toric shapefor correcting an astigmatism of the cornea 14. In certain embodiments,one or both shapes 214, 216 may be segmented or splined. For example,since spherical aberrations are generally less at smaller radii from theoptical axis, the shapes 214, 216 of the inner zone 230 and/or theintermediate zone 232 may be characterized by a sphere with a constantradius of curvature, while the shape 214 and/or shape 216 within theouter zone 234 is characterized by a polynomial equation such asEquation 1 or 2 above.

In certain embodiments, the optic 202 may comprise additional zonesbesides the zones 230, 232, 234, for example, comprising 4 zones, 5zones, or 6 zones in total. In such embodiments, a first set ofalternating zones may contain monofocal and/or multifocal diffractiveprofiles that are imposed on a base shape, while a second set ofalternating zones may contain multifocal refractive profiles that areimposed on a base shape (either on the same or opposite surface of theoptic). Alternatively, two (or more) adjacent zones may both (all)contain either a multifocal refractive profile, a multifocal diffractiveprofile, or a monofocal diffractive profile. In some embodiments, one ormore of the zones is a monofocal zone providing a single focus oroptical power (e.g., for providing near, intermediate, or distantvision), while one or more of the remaining zones include a multifocalrefractive profile and/or a multifocal diffractive profile. In any ofthese embodiments, one or both surfaces 204, 206 may contain a monofocaldiffractive profile or grating over all or a portion of one of thesurfaces 204, 206 that is configured to have only one focus at a designwavelength within the visible light band of the electromagnetic spectrum(e.g., to correct or compensate for a chromatic aberration of the optic202 or the eye 10).

In general, any of feature, properties, or fabrication methods discussedabove regarding the optics 102, 102′ may be incorporated, whereapplicable, into the optic 202, or visa versa. For example, any featuresof the shapes, surfaces, or profiles discussed in relationship to theoptics 102, 102′ may be incorporated, where applicable, into the optic202, or visa versa.

The above presents a description of the best mode contemplated ofcarrying out the present invention, and of the manner and process ofmaking and using it, in such full, cear, concise, and exact terms as toenable any person skilled in the art to which it pertains to make anduse this invention. This invention is, however, susceptible tomodifications and alternate constructions from that discussed abovewhich are fully equivalent. Consequently, it is not the intention tolimit this invention to the particular embodiments disclosed. On thecontrary, the intention is to cover modifications and alternateconstructions coming within the spirit and scope of the invention asgenerally expressed by the following claims, which particularly pointout and distinctly claim the subject matter of the invention.

What is claimed is:
 1. An ophthalmic lens, comprising: an opticcomprising a first surface having a first shape and an opposing secondsurface having a second shape, the shapes together providing a baseoptic power; a multifocal refractive profile imposed on at least one ofthe shapes over a first radial extent, the multifocal refractive profileincluding a refractive base power of about zero Diopters and arefractive add power between about 1 Diopter and about 3 Diopters; amultifocal diffractive profile imposed on at least one of the shapesover a second radial extent, the multifocal diffractive profile having,for visible light, a primary diffraction order, a secondary diffractionorder, and a diffractive add power corresponding to a difference inoptical power between the secondary diffraction order and the primarydiffraction order, the diffractive add power between about 1 Diopter andabout 3 Diopters; an overlap portion between the multifocal refractiveprofile and the multifocal diffractive profile defining an overlapaperture, the overlap aperture filled by a portion of the multifocalrefractive profile that includes both the refractive base power and therefractive add power, the overlap aperture also filled by a portion ofthe multifocal diffractive profile that includes the primary diffractionorder, the secondary diffraction order, and the diffractive add power;wherein the overlap portion has an add region and a base region, thebase region of the overlap portion configured for far viewing with therefractive base optic power and the primary diffraction order, the addregion of the overlap portion having a combined add power, over the baseoptic power, suitable for near viewing, the combined add power providedby a combination of the refractive add power and the diffractive addpower.
 2. The ophthalmic lens of claim 1, wherein the radial extentsbegin at the optical axis.
 3. The ophthalmic lens of claim 1, whereinthe first radial extent equals the second radial extent.
 4. Theophthalmic lens of claim 1, wherein the primary diffraction order is azeroth diffraction order having an optical power of about zero Dioptersand the secondary diffraction order is a first diffraction order havingan optical power that is between about 2 Diopter and about 8 Diopters.5. The ophthalmic lens of claim 1, wherein the primary diffraction orderis a first diffraction order, the secondary diffraction order is asecond diffraction order, and the add power being between about 2Diopters and 8 Diopters.
 6. The ophthalmic lens of claim 1, wherein theoverlap aperture has an outer boundary shape, wherein the outer boundaryshape is a circle having an outer diameter or an annular ring having aninner diameter and an outer diameter.
 7. The ophthalmic lens of claim 1,wherein the optic includes a clear aperture, the multifocal refractiveprofile filling the entire clear aperture, the multifocal diffractiveprofile filling the entire clear aperture, or both the multifocalrefractive profile and the multifocal diffractive profile fill theentire clear aperture.
 8. The ophthalmic lens of claim 1, wherein theoptic has an intermediate add power within the overlap aperture that isless than the combined add power, the intermediate add power being therefractive add power or the diffractive add power.
 9. The ophthalmiclens of claim 1, wherein the refractive add power is about 2 Diopter,the diffractive add power is about 2 Diopter, and the combined add poweris between about 3.5 Diopter and about 4.5 Diopters.
 10. The ophthalmiclens of claim 1, wherein the refractive add power is configured toprovide near vision or intermediate vision, the diffractive add power isconfigured to provide near vision or intermediate vision, or both therefractive add power and the diffractive add power are each configuredto provide near vision or intermediate vision.
 11. The ophthalmic lensof claim 1, further comprising an additional multifocal profile and anadditional overlap portion defining an additional overlap aperture thatincludes the additional multifocal profile, the additional multifocalprofile being a multifocal diffractive profile or a multifocalrefractive profile.
 12. The ophthalmic lens of claim 11, wherein theadditional overlap portion has an add power provided by the additionalmultifocal profile in combination with a multifocal profile.
 13. Theophthalmic lens of claim 1, wherein the diffractive profile has adiffractive efficiency of between 10% and 40%.
 14. The ophthalmic lensof claim 1, wherein the diffractive profile has a diffractive efficiencyof between 15% and 25%.
 15. The ophthalmic lens of claim 1, wherein thediffractive profile has a diffractive efficiency of between 25% and 35%.16. An ophthalmic lens, comprising: an optic comprising a first surfaceand an opposing second surface; a multifocal refractive profile imposedon at least one of the surfaces over a first radial extent, themultifocal refractive profile including a refractive base power and arefractive add power; a multifocal diffractive profile imposed on atleast one of the surfaces over a second radial extent, the multifocaldiffractive profile having, for visible light, a primary diffractionorder, a secondary diffraction order, and a diffractive add powercorresponding to a difference in optical power between the secondarydiffraction order and the primary diffraction order an overlap portionbetween the multifocal refractive profile and the multifocal diffractiveprofile defining an overlap aperture, the overlap aperture filled by aportion of the multifocal refractive profile that includes both therefractive base power and the refractive add power and a portion of themultifocal diffractive profile that includes the primary diffractionorder and the diffractive add power; wherein the overlap portion has anadd region configured for near viewing and a base region configured forfar viewing, the add region of the overlap portion having at least onecombined add power, over a base power of the base region, provided by acombination of the refractive add power and the diffractive add power;wherein the optic has an intermediate add power within the overlapaperture that is less than the combined add power, the intermediate addpower being the refractive add power or the diffractive add power. 17.The ophthalmic lens of claim 16, wherein the diffractive profile has adiffractive efficiency of between 10% and 40%.
 18. The ophthalmic lensof claim 16, wherein the diffractive profile has a diffractiveefficiency of between 15% and 25%.
 19. The ophthalmic lens of claim 16,wherein the diffractive profile has a diffractive efficiency of between25% and 35%.
 20. An ophthalmic lens, comprising: an optic comprising afirst surface having a first shape and an opposing second surface havinga second shape, the shapes together providing a base optic power; amultifocal refractive profile imposed on at least one of the shapes overa first radial extent, the multifocal refractive profile including arefractive base power of about zero Diopters and suitable for viewing atfar distances and a refractive add power of about 2 Diopters; amultifocal diffractive profile imposed on at least one of the shapesover a second radial extent, the multifocal diffractive profile having,for visible light, a primary diffraction order suitable for viewing atfar distances, a secondary diffraction order, and a diffractive addpower corresponding to a difference in optical power between thesecondary diffraction order and the primary diffraction order, thediffractive add power being about 2 Diopters; an overlap portion betweenthe multifocal refractive profile and the multifocal diffractive profiledefining an overlap aperture, the overlap aperture filled by a portionof the multifocal refractive profile that includes both the refractivebase power and the refractive add power, and a portion of the multifocaldiffractive profile that includes the primary diffraction order, thesecondary diffraction order, and the diffractive add power; the overlapportion having at least one combined add power provided by a combinationof the refractive add power and the diffractive add power, the combinedadd power between about 3.5 Diopter and about 4.5 Diopters andconfigured for viewing at near viewing distances.
 21. The ophthalmiclens of claim 20, wherein the diffractive profile has a diffractiveefficiency of between 10% and 40%.
 22. The ophthalmic lens of claim 20,wherein the diffractive profile has a diffractive efficiency of between15% and 25%.
 23. The ophthalmic lens of claim 20, wherein thediffractive profile has a diffractive efficiency of between 25% and 35%.